Process line for the manufacture of absorbent disposable articles

ABSTRACT

A production line for manufacturing absorbent disposable articles includes a conveyor path ( 3, 14, 15 ) which moves a web of material through the production line, and a row of devices ( 1, 4, 5, 6, 7, 8, 9, 11, 12, 13 ) which are arranged sequentially in the movement direction of the conveyor path and which perform different operations in the manufacture of the absorbent article. The devices are carried by rectangular carrier plates ( 29, 34, 35, 39, 47 ) which are attached to vertical posts ( 17 ) which, in a framework ( 16 ), are placed on the same side of the conveyor path and sequentially in a direction parallel with the movement direction of the conveyor path. The framework includes a plurality of connectors ( 27, 28 ) which connect to flowing media delivery lines, such as electric current and compressed air.

The present invention relates to a production line for the manufactureof absorbent disposable articles, such as diapers, sanitary napkins andincontinence guards, wherein the production line includes a conveyorpath which functions to move a web of material through the productionline, and a row of devices are arranged sequentially in the direction ofweb movement for carrying out different working operations included inthe manufacture of the absorbent article, these devices being carried onrectangular carrier plates which are attached to vertical posts whichare placed in a framework on mutually the same side of the conveyor pathand sequentially in a direction which extends parallel with thedirection of conveyor-path movement.

Absorbent disposable articles are typically produced by taking a web ofmaterial from a storage reel and moving the web past a number of deviceswhich perform different operations in sequence, such as placingabsorbent bodies on the web, laying-out elastic, applying glue, applyingfurther webs of material, compressing absorbent bodies, and heat-weldingor ultrasonic-welding the webs, and so on. In production of this nature,the production line has been traditionally constructed as one singleunit. In recent times, production development has accelerated withinthis particular technical field, necessitating comprehensivereconstruction of the production lines. However, production lines ofunit construction are less suitable for reconstruction and as a result,it has taken much too long to introduce new or modified products ontothe market, and it has often been necessary to refrain from making smallimprovements to existing products, because of the radical changes in theproduction lines that such an improvement would incur, while, at thesame time, the long non-productive times or down-time caused by suchreconstruction would prevent the market demand of such products beingmet, resulting in loss in profits and, in the longer term, perhaps alsoa loss in the share of the market.

The European Patent Application No. 93850174.9 teaches a production linefor the manufacture of absorbent disposable articles which overcomesthese drawbacks to a large extent. The various working devices of theproduction line are carried by mutually identical module plates whichcan be mounted in any desired position in a framework that extends alongthe production line. This design greatly facilitates reconstruction ofthe production line, while enabling the production line to be extendedby adding further working devices thereto, without needing to make largemodifications.

The primary object of the present invention is to further facilitaterestructuring of a production line and the addition of further workingdevices, in comparison with the aforesaid known production line. Asecondary object of the invention is to facilitate mounting of thecarrier plates in a production line, so that a large part of this workcan be carried out by technically unqualified personnel.

These objects are achieved in accordance with the invention with aproduction line of the kind defined in the introduction which ischaracterized in that the framework includes a plurality of mutuallyadjacent connections which are connected to delivery lines for flowingmedia, such as electric current and compressed air; in that each carrierplate supporting at least one working device, which is operated ormaneuvered by flowing media, also supports operating or maneuveringmeans and connecting elements for connecting the operating ormaneuvering means concerned to a corresponding connector on theframework; and in that the connectors on the framework and the connectorelements are so arranged that each connector element on a carrier platecan be connected to a connector on the framework irrespective of theposition of the carrier plate on the framework. This constructiongreatly simplifies fitting of a carrier plate in the production line,since all that is needed is to secure the plate to the framework and toconnect the connector elements to the nearest line fixed connector onthe framework. This fitting operation can be carried out very quicklyand with the aid of technically unqualified personnel. The downtime ofsuch a production line will be relatively short when changing or fittinga working device.

In one preferred embodiment of the invention, the framework includes atleast one row of sets of connectors for electric current and compressedair arranged sequentially in the direction of the conveyor path, whereinthese sets of connectors are separated by a distance which is equal to amultiple of the smallest distance between the vertical posts. Each setof connectors on the framework includes a databus connector, and eachcarrier plate supports a working device which includes a control meanswhich is connectable to the databus connector, and a connector-elementholder which is placed in the same position on each carrier plate.

The invention will now be described with reference to the accompanyingdrawings, in which

FIG. 1 is a schematic front view of one embodiment of an inventiveproduction line;

FIG. 2 is a schematic, perspective view taken obliquely from the frontof part of the framework and the carrier plates included in theproduction line illustrated in FIG. 1;

FIG. 3 is a perspective view taken obliquely from the rear of theframework illustrated in FIG. 2;

FIG. 4 is a perspective rear view of a carrier plate provided with aconnector element holder;

FIGS. 5 and 6 are respective top views taken from the rear and from theside of a carrier plate which supports a number of alternating currentmotors and compressed-air lines; and

FIGS. 7 and 8 are respectively a schematic side view and a schematic topview taken from the front of one embodiment of an inventive carrierplate.

FIG. 1 illustrates very schematically a diaper production line which, asseen in the direction of manufacture, i.e. from left to right in theFigure, includes a mat-laying wheel 1, a compression wheel 2, a transferwheel 3, a device 4 for feeding layers from a top and a bottomreel-stand, a pair of compression rolls 5, a transverse cutter 6, atransfer device 7, feeders 8, 9, a thread applicator 10, an adhesivetape applicator 11, feeder means 12, and a cutter 13. The productionline also includes means for conveying the diaper blank through theline, for instance the conveyors 14, 15 illustrated schematically in theFigure.

When manufacturing a diaper in the aforedescribed production line, themat-laying wheel 1 produces a layer of cellulose fluff which istransferred to the conveyor 14 with the aid of the compression wheel 2and the transfer wheel 3. The fiber mat then passes through the device4, in which a top and a bottom layer of tissue taken from storage reelsare delivered to the top and the bottom of the cellulose fluff mat orlayer respectively. These layers then pass together through the rollpair 5 and are compressed therebetween. This results in a coherent,continuous three-layer body which passes through the transverse cutter6, which produces individual absorbent bodies from the continuous,coherent three-layer body. A transfer wheel 7, also called anaccelerator wheel, places the absorbent body on a web of plastic film,for instance polyethylene film, which is taken from a storage reel inthe forward feed means 12 and advanced to the wheel 7 from right to leftin the Figure, and thereafter from left to right in said Figure with theindividual absorbent bodies spaced a given distance apart. Prior toarriving at the wheel 7, the plastic film passes the adhesive tapeapplicator 11, which provides the plastic film with a pair of fastenertapes, and will also have passed the thread applicator 10 which providesthe plastic film with appropriate elastic. The forward feed devices 8, 9function to lay two layers of nonwoven fabric, taken from reel standsincluded in said devices, on top of the plastic film web and theabsorbent bodies, and the top and bottom layers are fastened together insome suitable way, for instance by gluing or ultrasonic welding.Finally, the web of absorbent bodies enclosed between top layers, i.e.the two nonwoven layers, and bottom sheet, i.e. the plastic film, passthrough a cutter 13 by means of which complete diapers are cut from theweb.

The choice of appropriate known working devices capable of performingthe aforesaid functions lies in the normal competence of the personskilled in this field, and the design of the working devices 1-13 andthe conveyors 14, 15 included in the production line will naturallydepend on the type of diaper to be manufactured. The design, orconstruction, of the individual working devices forms no part of thepresent invention and the application will not therefore be laden with adetailed description of the components included in the production line.

In accordance with the present invention, the aforesaid working devicesare mounted in the production line on carrier plates which, in turn, aremounted on a framework 16.

FIGS. 2 and 3 are respectively schematic, perspective front and rearviews of parts of the framework 16 included in the production line. Theside of the framework facing the conveyors and the viewer of FIGS. 1 and2 is the front side of the framework. The framework 16 is constructedfrom two parallel rows of front and rear vertical posts 17 and 18respectively, which are evenly spaced in the rows. The mutuallysequential posts 17 and 18 in said rows are connected together by topand bottom cross-bars 19, 20 and 21, 22 respectively, and mutuallyopposing posts in the working direction of the production line arejoined together by additional top and bottom cross-bars 23, 24.Naturally, further cross-bars may be included if necessary formechanical strength reasons, although this is avoided if possible, atleast in the front row of posts 17, so as not to restrict thepossibility of positioning working devices on carrier plates attached tothe framework. The bottom cross-bars 24 extend beyond the front posts17. The framework rests on a carrier frame 25 which includesheight-adjustable legs 26.

As illustrated schematically in FIG. 3, cable ladders 27 are arranged onthe rear vertical posts 18. These cable ladders include heavy-currentconductors and weak-current conductors through which current is suppliedto the working devices of the production line, and a network cable isalso connected to a central computer. Arranged within the front verticalposts 17 are compressed-air lines, and a row of compressed-air outlets28 is placed along the length of said posts.

As before mentioned, the working devices are carried by carrier plates,which are screwed firmly to the front vertical post 17 of the framework16. The size of these carrier plates is adapted to a large extent to thesize of the working device which the plate concerned is intended tocarry or support, as indicated in FIGS. 1 and 2, which makes theproduction line highly flexible. FIG. 2 illustrates an example of howthis flexibility can be utilized. The Figure shows a carrier plate 29which carries a roll pair 30 driven by an alternating current motor 31.The plate 29 also carries a gluing unit 32 provided with a slot-shapednozzle (not shown) and a guide roller 33. Also shown in FIG. 2, inbroken lines, is a first web of material I which is glued to a secondweb of material II in the nip of the roll pair 30, this web II havingpassed beneath the glue nozzle of the glue applicator 32 prior toentering the roll nip. If it is later decided that the webs I and II canbe joined together equally as well with glue beads, the carrier plate 29can be removed quickly and easily from the framework 16 and replacedwith another carrier plate that carries a different type of glueapplicator. In the FIG. 2 illustration, the carrier plate 29 has beenreplaced with two carrier plates 34 and 35, which carry a glueapplicator 36 which includes a row of glue nozzles, and a guide roller37 and a driven roll pair 38 respectively. The carrier plates 34, 35have the same width as the carrier plate 29, but are only half as high.

FIGS. 3 and 4 are schematic, perspective rear views of a carrier plate39 which carries a working device, for instance a driven roll pair,whose drive motor 40 is mounted on the rear side of the carrier plate39. The drive motor 40 is comprised of an alternating current motorwhose output shaft passes through the carrier plate and coacts with theworking device (not shown) mounted on the front: of the plate. The drivemotor is connected, by conductors not shown, to safety switches 41mounted on a holder 42. The safety switches can, in turn, be connectedto the nearest cable ladder 27 on the framework 16, with the aid ofappropriate connectors, for instance plug-in connectors. The holders 42are always arranged in the same position on a carrier plate that carriesa working device, more specifically in the upper right-hand corner ofthe illustrated inventive carrier plate, as seen from the front. As aresult, there is only a short distance between holder and the nearestcable ladder, meaning that a short conductor can be used from the holder42, one end of this conductor being connected to the male part of theplug-in contact. In order to make this length of the conductor short,several female connector parts are spaced in the height direction alongthe cable ladders.

The holder 42 also carries a control unit 43 by means of which theworking device is controlled, this unit, in turn, being connected to acentral computer which controls all working devices included in theproduction line, via the network cable or conductor in the cableladders. The holder 42 also carries a compressed-air unit 44, which isconnected to the nearest compressed-air outlet 28, by means of asuitable hose coupling. As shown schematically in FIG. 4, the unit 44includes a row of compressed-air valves 45, from which air-lines lead topneumatic piston-cylinder devices (not shown) included in the workingdevices mounted on the front side of the carrier plate. Pneumatics arenormally used to move the working devices into and out of theirrespective working positions, for instance to move the rolls of a rollpair towards and away from one another, although other applications,such as pneumatic motors, can be used within the scope of the invention.FIG. 4 also shows a pipe 46 which can be connected by means of asuitable hose coupling to a sub-pressure source, for instance a vacuumbox, which is often positioned beneath a conveyor in the production lineprovided with a row of coupling outlets. Naturally, it is also possibleto provide a pipe system which is connected to a sub-pressure source inor outside the vertical posts 17 or 18 in a manner similar to thecompressed air supply arrangement, or to provide a row of couplingoutlets along the posts. As will be understood, hydraulic fluidconnections may also be arranged in the rows of connector arrays whenhydraulic motors are used in the production line.

FIGS. 5 and 6 illustrate another carrier plate 47 on which fivealternating current motors 48, 49, 50, 51 and 52 are mounted, of whichonly the motors 50-52 are shown in FIG. 6. The motor 52 drives a shaftor axle 53, via a belt 54 shown in chain lines in FIG. 5. The workingdevices mounted on the front side (not shown) of the carrier plate maycomprise a cutter which is operated by two drive motors, and a combinedtransporting and compressing unit which uses three motors. Similar tothe case of the carrier plate 39 shown in FIGS. 3 and 4, aconnector-element holder 55 is attached to the carrier plate 47 andplaced in its upper right-hand corner as seen from the front side of thecarrier plate. The holder supports a compressed-air unit 56 and a set ofcompressed-air valves 57 and a set 58 of safety switches for the motors48-52. The holder 55 also carries a control unit 59, which is connectedto the network cable via a data bus connection. The carrier plate 47 isprovided along both of its edges with a row of holes 61 through whichthe bolts used to screw the plate to the framework are inserted. Inorder to enable the carrier plate 47 to be fitted more easily, so thatthese holes will lie in register with corresponding screw-threaded holesin the framework posts, the carrier plate is also provided with guidepins 60 which are intended to coact with appropriate guide surfaces onthe framework posts, for instance upwardly extending V-shaped surfaces,so as to ensure that the plate will be brought quickly to its correctposition.

The control units 43, 59 include all components necessary to regulateindividual operation of the working devices carried by the carrier plateor carrier plates 39, 47, and can therefore be operated from outside theproduction line, therewith enabling the function of a repaired workingdevice to be tested without needing to first replace the repairedworking device in the production line. The primary purpose of thecentral computer is to synchronize operation of the different workingdevices in the production line and to monitor working of the productionline so as to stop work as soon as one of the working devices is foundto malfunction.

FIGS. 7 and 8 illustrate schematically a further embodiment of aninventive carrier plate 62. This carrier plate differs from the carrierplate 47 shown in FIGS. 5 and 6 essentially by virtue of including twoholders 55′, 55″ arranged one after the other along the right edge-partof the carrier plate 62, and also by virtue of including a row offastener holes 61′, 61″ along all edges of the plate. The working devicemounted on the carrier plate 62 has not been shown in these Figures forthe sake of clarity. Components that correspond to similar components inFIGS. 5 and 6 have been identified by the same reference signs to whicha prime and double-prime have been added in FIGS. 7 and 8. Because theplate 62 includes a row of fastener holes 61′, 61″ along each edge, thecarrier plate can be mounted with the two opposing rows 61′ or the twoopposing rows 61″ coacting with rows of holes (not shown) in the posts,therewith further increasing the flexibility of the production line.With the intention of facilitating fitting of a carrier plate, the guidepins 60′, and also the guide pins 60 shown in FIGS. 5 and 6, are mountedon the plate 62 in a manner which enables the pins to be readily fittedand removed, by screwing the pins into and out of sockets or sleeves63′, 63″ in the plate 62.

As the size of the carrier plates is determined essentially by the sizeof the working device or devices that the plates are intended to carry,the space for accommodating each working device in the production lineis also determined in practice by the size of the device. However, thedimensions of the carrier plates must be proportionate to one another ina particular manner, so as to enable the plates to be exchanged and toachieve the desired flexibility of the production line. Thus, the sizesof the carrier plates must be such as to enable each carrier plate to bereplaced with or exchanged for one or more other carrier plates. To thisend, the lengths of the sides of the carrier plates are essentially amultiple of the length of the smallest side of the smallest carrierplate, and the carrier plates are so dimensioned that each carrier platewill include a pair of opposing sides whose lengths are generally equalto or comprise generally a multiple of the distance between the posts17. The fact that the lengths are not exact multiples of the length ofthe smallest side of the smallest carrier plate is due to the fact thecarrier plates shall be spaced some small distance apart on theframework, so as to make fitting and dismantling of the plates easier.For practical reasons, this distance should be at least 2 mm and thelength of the smallest side of the smallest plate should be at least 400mm.

The working devices of the inventive illustrated production line aremounted by placing the carrier plates supporting the working devicesincluded in the production line in place in the framework and screwingthe plates securely thereto. The quick-couplings of the holders 42, 55intended for the delivery of flowing media, i.e. electric current,compressed air, etc., are then coupled to the delivery linen provided inthe framework, and the control devices 43, 59 controlling the workingdevices are connected to the central computer by means of databusconnections. The production line is ready to be put into operation whenall working devices have been secured and connected-up. Fine adjustment,or trimming, of the fitted working devices is unnecessary, since thesedevices are constructed as independent units which possess their owndrive means and control units, the different operations of which arecontrolled and synchronized by a central computer. It thus suffices tocheck that the individual working devices function in the mannerintended. To replace or add a working device in the production line, isthus a measure that can be performed quickly therewith making thedowntime for such a measure short. Furthermore, adaptation of the sizeof the carrier plates to the size of associated working devices enablesavailable space on the framework to be utilized more effectively, sothat additional working devices can be added to the production linewithout requiring comprehensive restructuring. Because each carrierplate that supports a working device forms an independent unit which canbe operated independently, comprehensive restructuring of the productionline can also be effected in a very short period of time; in theory, theminimum restructuring time is the time taken to remove one carrier plateand fit another.

The vertical posts 17 included in the framework 16 are preferablysecured to the remainder of the framework in a manner which enables theposts to be easily dismantled. This enables posts that are locatedbehind carrier plates of such size as to extend between three sequentialposts 17 in the Figures to be dismantled so as not to be in the way ofworking devices mounted on such a plate. When the plate does not extendalong the full height of the framework, a cross-bar is suitably fittedbetween the posts so as to give further support to the plate. To thisend, the vertical posts are conveniently provided with a row ofcross-bar attachments extending along the length of said posts.

As indicated in FIGS. 1 and 2, the outer surfaces of the framework 16are completely clad with carrier plates, even at those places where noworking devices are carried. Although not shown in the drawings, stripsare arranged in the spaces between mutually adjacent carrier plates.These strips may have the form of sealing strips provided with resilientsealing lips and will be of a nature that enables them to be fitted andremoved easily. The interior of the framework is thus a closed space.This prevents dust and dirt from reaching the operating and controlcomponents that are enclosed in this space and, at the same time,enables an appropriate type of cooling unit (not shown in the drawings)to be placed in the centre of the space for central cooling of saidcomponents. It is pointed out that the rear and side walls of theframework need not be comprised of carrier plates according to theaforegoing, but may be comprised of conventional wall elements to nodisadvantage, wherein a door which provides access to the interior ofthe framework may be provided in one of these walls.

As shown in FIGS. 2 and 3, the bottom cross-bars 24, which extendforwardly beyond the front posts 17 transversely thereto are alsocovered with carrier plates. According to one variant of the invention,the conveyors are mounted on these plates by means of quick-couplings,to facilitate fitting of the carrier plates secured to the posts 17.

In the described embodiment, the production line is comprised of carrierplates of different sizes. It will be understood, however, that theinvention can also be applied in production lines comprised of carrierplates that have mutually the same size.

It will be understood that the described and illustrated exemplifyingembodiment of an inventive production line can be modified in many wayswithin the scope of the invention. For instance, the framework mayinclude props or braces between the posts 18, for supporting heavyworking devices that project far out from the plate and therewithprevent such devices from bending. Correspondingly, props or braces canbe attached to the carrier frame 25 on the front side, so as to preventbending of long rolls. It is also possible to provide the framework withglue delivery connections. Furthermore, the sets of connections may befitted to solely each alternate rear post 18. In this case, it may beconvenient to place the connector holders of two mutually adjacent,laterally positioned carrier plates on laterally opposite sides of thecarrier plates. Thus, the invention includes all constructions in whichthe distance between connector sets in said rows of connectors form amultiple of the smallest distance between the vertical posts and thoseconstructions in which the holders are placed on several standardizedlocations along the edge parts of the plates. The roof of the frameworkmay also be used to support particularly bulky working devices, such asreel racks, for instance. Sealing strips may also be placed along theopposing front edges of the posts, within the region of the fittedcarrier plates, wherein only those horizontal spaces between the platesneed be covered by sealing strips. The invention is therefore limitedsolely by the content of the following Claims.

What is claimed is:
 1. A production line for manufacturing absorbentdisposable articles, wherein the production line includes a conveyorpath (3, 14, 15) which moves a web of material through the productionline, and a row of devices (1, 4, 5, 6, 7, 8, 9, 11, 12, 13) whichreceive operating energy from a flowing media and which are arrangedsequentially in the movement direction of the conveyor path and whichperform different working operations in the manufacture of the absorbentarticle, wherein said devices are carried by rectangular carrier plates(29, 34, 35, 39, 47) which are attached to vertical posts (17) which areplaced in a frame-work (16) on the same side of the conveyor path andsequentially in a direction parallel with the movement direction of theconveyor path; a plurality of connectors (27, 28) which connect to linesfor the delivery of the flowing media, one of said connectors beingprovided for each pair of said vertical posts carrying at least one ofsaid carrier plates; in that each of said carrier plates (29, 34, 35,39, 47) carries associated operating means (31, 40, 48-52) for operatingone or more of the devices carried by the respective one of said carrierplates and connector elements (41, 44, 45, 56, 57, 58) for connectingthe operating means to a corresponding one of said connectors (27, 28)on the framework, wherein said connector elements carried by therespective said carrier plate are connected to said connectors in theone of said pair of vertical posts carrying the respective said carrierplate; and in that said connectors and said connector elements are soarranged that each said connector element can be connected to one ofsaid connectors on the framework irrespective of the position in whichthe carrier plate is placed on the framework.
 2. A production lineaccording to claim 1, wherein the framework (16) includes at least onerow of sets of connectors (27, 28) for electric current and compressedair, wherein said connector sets are disposed sequentially in themovement direction of the conveyor path and are mutually spaced by adistance which constitutes a multiple of the distance between thevertical posts (17).
 3. A production line according to claim 2, whereineach set of connectors on the framework includes a databus connection;and in that each said carrier plate (39, 47) carrying a working one ofthe devices includes a control unit (43, 59) connectable to the databusconnection.
 4. A production line according to claim 1, wherein each saidcarrier plate (39, 47) which carries a working one of the devicesincludes a holder (42, 55) for said connector elements (41, 43, 44, 45,56, 57, 58) which are placed in an identical position on each of saidcarrier plates.
 5. A production line according to claim 4, wherein atleast one of the carrier plates (62) carrying at least one of theworking devices includes plural connector-element holders (55′, 55″)placed sequentially along one side-edge part of the carrier plate.
 6. Aproduction line according to claim 1, wherein each said carrier plate(62) whose sides all have a length which is generally equal to orexceeds the smallest distance between the posts (17) can be fastened tothe framework in at least one first position and in at least one secondposition which corresponds to rotation of the plate (62) through 90° inits plane relative to the first position.
 7. A production line accordingto claim 1, wherein a plurality of said connectors comprise a row ofcable ladders (27) which each extend vertically adjacent one of thevertical posts (17) in the framework, wherein the cable ladders includemale and female devices which can be connected to female or male devicesconnected to a holder (42, 55) on a one of the carrier plates supportinga working one of the devices.
 8. A production line according to claim 7,wherein the cable ladders (27) include a plurality of vertically spacedmale or female devices.
 9. A production line according to claim 7,wherein the cable ladders (27) extend vertically opposite each verticalpost (17) in the framework (16) with the exception of one of the twooutermost ones of the vertical posts.
 10. A production line according toclaim 1, wherein said connectors comprise at least one compressed-airoutlet (28).
 11. A production line for the manufacture of absorbentdisposable articles, comprising: plural carrier plates, each forcarrying at least one device used in the manufacture of the absorbentdisposable articles, each device being powered by flowing media; aframework comprising vertical posts, each of said carrier plates beingcarried by at least two of said vertical posts so that the devicescarried by said carrier plates are sequentially arranged for themanufacture of the absorbent disposable articles; a connector carried inone of each set of the two vertical posts carrying one of said carrierplates, each of said connectors being connected to a source of theflowing media; and each of said carrier plates further comprising areceptor for conveying the flowing media to the device on thecorresponding one of the carrier plates and for being connected to theone said connector on the one of the vertical posts carrying thecorresponding one of the carrier plates.
 12. The production line ofclaim 11, wherein a distance from said receptor to said correspondingconnector is less than a distance between two adjacent said verticalposts.